I receive an error saying the the User Name and E-mail do not exist, even though I know they are valid.

I entered a valid User Name and E-mail; however, I am receiving the following error when I click Submit: The User Name and E-mail you provided could not be matched with an existing SharePoint User Profile located at http://localhost/. Please contact your System Administrator for further assistance.
CAUSE
There are several scenarios that may generate this error message: The Web Service URL does not point to the correct Top-Level site where the user resides. The provided e-mail does not match what is currently configured in the User Information List found in the Site Administration page.
RESOLUTION
In order to allow this Web Part to work on Anonymous web sites, we added the ability for the user to designate where the top level site exists so it would be possible to have the anonymous web site on a different site or virtual server altogether.  To build the appropriate Web Service URL: Log into the SharePoint site where the users reside.  Go to Site Settings. Click Go To Site Administration in the General Settings (for Portal Server)/ Administration section (for WSS). Click Manage Users.  Confirm that the user you are expecting is present there.  Copy the URL to a document editor program.  It will look something like this: http://sps-qa4/sites/TestSite/_layouts/1033/user.aspx Remove the text beginning with _layouts. The remaining text should look something like this: http://sps-qa4/sites/TestSite/ Open the Web Part Properties of the Password Reset Web Part, expand Password Reset Configuration. Locate the section labeled Web Service URL. Paste the newly formed path in the field. To confirm the User Name and E-mail configuration on the SharePoint environment: Log into the SharePoint site where the users reside.  Go to Site Settings. Click View information about site users. This information is used by the Password Reset Web Part to confirm your User Name and E-mail address.